"I can't believe we did it. I can't believe we made it." Those were the first thoughts of the Seattle woman who, with her younger brother, reached shore after swimming for 14 hours off the coast of St. Lucia Sunday.

The siblings' journey to survival began just as Dan Suski was reeling in a nearly 400-pound marlin aboard their chartered fishing vessel.

"I was getting tired about 45 minutes in and heard a loud noise and looked back into the cabin and the captain looked back at us and went in and saw that there was some water in the fore cabin and then looked in the engine compartment which was basically probably about 70 percent full," Dan Suski, of San Francisco, said on "GMA." "And then minutes later, it seems like, it was going down."

As the 31-foot boat sank, the Suskis and the crew members on board - the captain and first mate - strapped on their life jackets and jumped into the open water. The foursome floated next to the boat for one hour, at the captain's suggestion, until they all decided to swim for land.

"I actually felt very anxious just sitting and waiting," Kate Suski said. "I was starting to get very cold so when I was moving I felt a lot better."

"Eventually we all decided together to start swimming and then we saw a plane fly over and then a helicopter so we figured they were looking for us," she said. "They were between us and land so we started swimming faster to try and reach them but they disappeared and flew, I think, back to land."

As the plane overhead disappeared from the siblings' sight, so too did the captain and first mate, lost from their view in the swelling waters.

Nearing 14 hours in the sea, the Suskis kept their eyes on searching for land, all the time just hoping they were swimming in the right direction.

"We knew based on the wind direction that we were going pretty much towards land but when it would disappear the fear set in and we just didn't know where we going and then any number of things the sharks, hypothermia, dehydration," said Dan Suski. "All those things crossed our minds, I think, as we were swimming in."

Finally the siblings made it to a sliver of beach but knew their journey was not yet over.

"We knew we had a ways to go because we were at a pretty remote part of the island when we landed," said Kate Suski.

The pair said they spent the night eating bananas and mangoes. The next day they hiked until they found a farm worker who alerted authorities.

The Suskis were hospitalized and treated for dehydration and various injuries. The captain and first mate were in the water for nearly a day before a private boat owner plucked them to safety.

"We're doing pretty good all things considered," said Kate Suski, adding their only lingering injuries are "some joint pain, especially the ankles and the shoulder."

St. Lucia's maritime affairs unit is investigating the cause of the shipwreck.